<html><head>
  <title>:checked pseudo-class</title>
  <style type="text/css">input, span { background-color : red }
input:checked, input:checked + span { background-color : lime}
</style>
  <link rel="author" title="Daniel Glazman" href="http://glazman.org/">
  <link rel="author" title="Ian Hickson" href="mailto:ian@hixie.ch">
  <link rel="help" href="https://www.w3.org/TR/css3-selectors/#selectors"> <!-- bogus link to make sure it gets found -->
  <meta name="flags" content="">
 </head>
 <body>
<p>
<input type="checkbox" checked="checked"> <span>Everything in this paragraph should have a green background</span></p>

</body></html>